FIG. 1 is a schematic illustration of a media system. The media system 100 may receive media from a variety of sources—with source #1, source #2, and source #3 shown in FIG. 1. A source may be any type of information (e.g. audio, video, or data) and may be digital or analog. A source may represent a program (e.g. a television or video program such as but not limited to, a movie, a news cast, a sports or other event program), or a portion of a program. In some examples, sources may include combinations of audio, video, and/or data information. Examples of data information include, for example subtitles or other digital information.
The information from the sources may be encoded by an appropriate encoder, e.g. the encoders 105-107 shown in FIG. 1. The encoders 105-17 may encode the source information in any known way, for example, to compress the information. The encoders 105-107 may implement any appropriate encoding methodology for the information including, but not limited to MPEG-2, MPEG-4, H.264, H.HEVC, or combinations of these or other encoding standards. Encoded data may then be provided to a transport multiplexer 110.
The transport multiplexer 110 may receive the encoded data from multiple sources, and interleave them into a transport stream 115. The transport multiplexer 110 generally provides the received data as packets on the transport stream 115. Each transport stream packet may conventionally be 188 bytes, with a 4 byte header identifying the packet followed by control data, optional timing information, and a section of compressed data from one of the sources. A bitrate of the transport stream 115 is typically constant, e.g. the number of transport stream packets transmitted per second may be fixed. Stuffing packets may accordingly be inserted by the transport multiplexer 110 when insufficient data is available to fill the target bitrate.
Accordingly, the transport multiplexer 110 may serially provide packets of encoded data from selected sources to the transport stream 115. The transport stream 115 may be provided to any number of destinations that may unpack and decode the transport stream 115 and/or re-broadcast the transport stream 115. Examples of destinations include a satellite 120, terrestrial antenna 121, and network 122. Playback devices (e.g. set-top boxes) may also receive and decode the transport stream 115 for playback in some examples.